But for two days only, until possibly severe thunderstorms roll in on Sunday, we should be blessed with some good weather.

Unfortunately that’s not the only ‘blue’ that’s visiting us right now.

An armada of bluebottles has been washing up on Northern NSW beaches for the past week. 

Along with the general murkiness of our coastal waters after the rain gave our waterways a solid flushing out, and the wrong winds for a good surf, these little stinging blighters have made for some pretty terrible beach conditions, of late.

Still, if you enjoy walking or pottering around on the sand, tomorrow might yet be a good day to head to the beach.

Keen observers may have noticed not one, but two distinct varieties of royal blue fellas on our beaches.

While the puffy guys, with the long winding tentacles, are the common bluebottles (also known as Portuguese Man-of-Wars), the others resemble a flat 50 cent piece-sized disc with a small stiff transparent sail that catches the wind and propels them over the surface of the sea.

They’re from the same family of animals as bluebottles and jellyfish (cnidarian), but these guys are called Velella velella – or more commonly known by the names sea raft, by-the-wind sailor, purple sail, little sail, or simply velella.

Under certain wind conditions, they may be stranded by the thousands on beaches, which is what we’ve been witnessing this past week.

A pair of avid local surfers – Johnny and Terry – were checking out the conditions down at Main Beach, Nambucca, this morning and explained that the velellas are brought in whenever there’s a strong nor’easterly, which also tends to turn the water a dirty green colour. 

They said the little sea rafts are more annoying than painful – “like a sandfly sting”.

“Still, you won’t see me going for a swim at the moment,” Johnny said.

A velella's nematocysts (the explosive cells responsible for unleashing a painful toxin to subdue prey) are relatively benign to humans, although each person may respond differently to contact with the nematocyst toxin.

It is wise to avoid touching one's face or eyes after handling velellas, and itching may develop on parts of the skin that have been exposed to the nematocysts.

But a common bluebottle’s tentacles can still give you a painful sting even after they have washed up on shore.

So if you plan to take advantage of the brief respite from the rainy conditions tomorrow, make sure you avoid stepping on the blues with bare feet – unless you also relish the hilarious popping sound they make when you stomp on them. 

Here’s what to do if you get stung this weekend:

Bluebottles may not be everyone’s favourite but they are worth a closer look. 

Each bluebottle is actually a colony of animals, and is related to corals, jellyfish and sea anemones since they all use stinging cells to catch their food.  

One individual swells up with gas and becomes the float.  It is oriented at 45 degrees, half the population to the right and half to the left so that not all colonies will drift in the same direction.

The underside of the float is an oval disc which secretes the gas, a slightly different composition in every bluebottle and different to air. The oval disc also has a cavity which acts as a common stomach for all the other individuals in the colony.

The rest of the colony is made up of many groups of polyps suspended from the float.  Each group has three types of polyps.  

One is a feeding polyp with a sucker-like mouth at the end furthest from the float.  Another is the fishing polyp which is long and string-like with stinging cells.

These cells are triggered by touch, firing a barbed dart and poison into the small animals on which the colony preys.

The fishing tentacles retract to deliver their catch of small fish or zooplankton to the feeding polyps which digest the food and share it with the colony.

The third polyp is branched with two types of branches.  One type produces sperm and the other type eggs.  A fertilized egg develops into a larval polyp which grows into a float for a new colony.  Buds from it develop into all the other types of polyps. 

The organism has few predators of its own; one example is the loggerhead turtle, which feeds on the Portuguese man-of-war as a common part of its diet. The turtle's skin, including that of its tongue and throat, is too thick for the stings to penetrate.

The blue sea slug Glaucus atlanticus specializes in feeding on the bluebottle, as does the Janthina violet snail.

The blanket octopus is immune to the venom of the Portuguese man-of-war; young individuals carry broken man-of-war tentacles, presumably for offensive and/or defensive purposes, and the ocean sunfish's primary diet consists of jellyfish, but it also consumes bluebottles.

How our HSC kids are handling their exams

All the action from the Go Fishing day